Hematuria

There are two main types of hematuria:

• Gross hematuria. In this type of hematuria, the blood is visible in the urine.
• Microscopic hematuria. In this type of hematuria, the blood in the urine can only be seen under a microscope.

The most common cause of hematuria in children is familial hematuria. Familial hematuria is a condition in which many members of the same family experience blood in the urine without any other apparent problems in the kidneys or urinary system.

Other activities or conditions that can cause hematuria include:

• Vigorous exercise
• Trauma (injury) to the kidneys or urinary tract
• Kidney or bladder infection
• Kidney stones and related conditions, such as high urine calcium
• Diseases that cause damage to the kidney filters (these may be inherited problems or related to problems with the body’s immune system)
• Structural abnormalities of the kidneys and lower urinary tract (such as cysts or—very rarely—tumors)

Menstruation and by-products of certain foods and medicines can sometimes be mistaken for hematuria.

Diagnosis of Hematuria

If your child is experiencing blood in his or her urine, it is important that your child’s doctor evaluate it to determine what is causing the presence of blood. First, your pediatrician will gather a complete medical history for your child. Then, he or she will complete a thorough physical examination. This information will help your pediatrician decide which diagnostic tests should be performed to help make a diagnosis. These tests may include some or all of the following:

• Urinalysis. A urinalysis is a laboratory examination of urine that looks for abnormalities in appearance and substance, such as elevated levels of red blood cells, white blood cells or protein. These abnormalities may indicate kidney/bladder infection or kidney disease. In addition, urine may be tested for substances such as calcium. Too much calcium in the urine can cause irritation and bleeding in the urinary tract.
• Urine culture. A urine culture is a laboratory test to determine whether bacteria are growing in the urine. A positive urine culture indicates that a urinary tract infection is present.
• Blood tests. Blood tests look for high levels of waste products in the blood, which may indicate that the kidneys are not functioning properly and may be used to determine whether the immune system is functioning abnormally.
• Ultrasound. An ultrasound is a test that uses sound waves to produce high-quality images of the kidneys and bladders, without causing discomfort to the child. This allows your doctor to detect problems such as kidney stones, structural abnormalities and obstructions to the flow of urine.
• Cystoscopy. A cystoscopy (also called a cystourethroscopy) is an examination of the inside of the urethra and bladder. The exam involves inserting a cystoscope—a flexible tube equipped with a camera—through the urethra and into the bladder. A pediatric urologist performs this exam, and it may be used if a structural problem in the urinary tract is suspected. It is usually performed on an outpatient basis under sedation.
• Kidney biopsy. A kidney biopsy is a test in which a small piece of kidney tissue is obtained for study under a microscope. This test may be used to evaluate hematuria, especially if there are other signs of kidney disease present, such as proteinuria, high blood pressure or evidence that the kidneys are not working properly to remove waste products from the body.